The TOTEM collaboration has developed and tested the first prototype of its Roman Pots to be operated in the LHC. TOTEM Roman Pots contain stacks of silicon detectors with strips oriented in two orthogonal directions. To measure proton scattering angles of a few microradians, the detectors will approach the beam centre to a distance of 10 σ + 0.5 mm (= 1.3 mm). Dead space near the detector edge is minimised by using two novel "edgeless" detector technologies. The silicon detectors are used both for precise track reconstruction and for triggering. The first full-sized prototypes of both detector technologies as well as their read-out electronics have been developed, built and operated. The tests took place in the proton beam-line of the SPS accelerator ring. In addition, the pot's shielding against electromagnetic interference and the longitudinal beam coupling impedance have been measured with the wire method. ROMAN POTS FOR THE TOTEM EXPERIMENT AT LHCThe LHC experiment TOTEM [1] is designed for measuring the elastic pp scattering cross-section, the total pp cross-section and diffractive processes. These physics objectives require the detection of leading protons with scattering angles of a few µrad, which is accomplished with a Roman Pot ("RP") system having stations at 147 m and 220 m from the interaction point 5 where CMS will be located. Each station is composed of two RP units separated by 2.5 -4 m depending on beam equipment integration constraints. Each RP unit consists of a vacuum chamber equipped with two vertical insertions (top and bottom) and a horizontal one. Each insertion ("pot") contains a package of 10 silicon detectors in a secondary vacuum. The pots can be moved into the primary vacuum of the machine through vacuum bellows. In order to minimize the distance of the detectors from the beam, and to minimize multiple scattering, the wall thickness of the pot is locally reduced to a thin window foil (140 -210 µm).The low impedance budget of the LHC machine (broadband longitudinal impedance limit Z/n ≈ 0.1 Ω) imposes a tight limit on the RPs' beam coupling impedance. Because of the beam's bunch structure and its high intensity, the pick-up noise on the detector electronics caused by electromagnetic leakage is a potential concern and needs to be studied and minimised. THE ROMAN POT PROTOTYPE IN THE SPS BEAMDuring the summer 2004 the TOTEM collaboration has performed tests on a prototype unit made of 2 vertical RPs. The unit has been installed in the LSS5 section of the SPS accelerator at CERN. The motors moving the pots towards the beam, the electronics of the detectors and the cooling system stabilising the temperature of the detectors inside the pots were operated remotely from a temporary control room in a surface building. The upper and lower pots contained each a set of 8 silicon strip detectors with 66 µm pitch, built in two novel technologies allowing for efficiency up to the physical edge [1]. Six of them were read out with analogue APV25 chips and 2 with digital VFAT chips delivering...

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Analysis techniques in LHCf are presented, in which all techniques are required to have a high resolution and efficiency in order to overcome the severe situation, small lateral aperture and longitudinally short length of the detector. In this paper, methods for reconstructing an energy of electromagnetic shower are discussed following the data flow of measured data and Monte Carlo simulations.

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